Improvement in methods of sharpening files



UNITED STATES PATENT GFFICE.

4WILLIAM B.- GILLETT, On AUBURN, NEW YORK.

IMPROVEMENT IN METHODS AO|= SHARPENING F|| Es,"&c.

Specification forming Vpart of Letters Patent No. 27,046,'dated February 7, 1860.

To all whom it may concern:

Beit known thatI, WILLIAM B. GILLETT of Auburn, in the county of Cayuga and State of New York, have invented a new and Improved Mode of Becutting or Sharpening Worn-Out Files; and I do hereby declare that the following is a full and exact description thereof', reference being had to the accompanyingdrawngs,and toletters of reference marked thereon.

, through the said solution in such a mannerA The nature of my invention consists in decomposing a solution ot' acid or of asalt by passinga current of electricity or galvanism that the oxygen o'rother corrosive element,

that metal a galvauic battery. The tile, being connected by a wire with the platinum of the battery, is immersed vin abath of sulphuric acid diluted with about four parts of water to one of acid; or a solution of any suitable salt in water may be used?. A metallic plate, being' connected by a wire with the zinc of the battery, is also' immersed lin the same solution with the tile. I find it convenient .to use instead of the said metallic plates a lining of sheet vmetal `covering the inner surface of a box to contain the acid, the said lining of `sheet metal being connected with, the zinc of the battery' by arwire'; but the metallic plate above mentioned will serve to illustrate the principle.

In the accompanying drawing, A repre sents a Groves battery, ot' which B is the outside cup, of earthenware or glass; C, the cylinder, Ot'ziuc; D, the poroua'earthen cup; E, the platinum; F Gyscrews'ffor attaching wires; H, insulator; I, wire `connecting the file with the platinum; J,.le; K, acid bath;

L, metallic plate; M, wire connecting the plate .with the zinc of the battery.

'porous cup D. l The current is! attracted by the platinum and conducted by the wire I to the file J, passing through the acid or saline solu,y 1t is conductedtol tion to the metallic plate L. the zinc C by the wire M, thus making acomplete circuit. In' passing through the acid. or

saline bath K the electricitydecomposes thel The oxygen acid or salt, and also the water. or other corrosiveelement attacks the lile, dissolving and carrying Oft' the particles of metal along with the hydrogen to the metallic plate. By moving the metallic plate nearer to any part of theiile the action is increased at that part, thus enabling the operator to control the operation. By increasing or diminishingr the number of cupsin the battery the action upon the [ile is increased or diminished.

By the above-described process I am en- .abled to recut or sharpen and Arender tit for use worn-out rasps and files of every descrip tion without removing the temper or in any way injuring the quality ot' the steel. When the operation is conducted with Ordinary care the teeth are made quite sharp and out equally as well as new les.

Before commencing to cut tiles by the above" described process they should be made clean by boiling in a strong alkaline solution or any other suitable method.

When the files are sutciently acted upon by the above process, which maybe known by feeling the points or edges ofthe teeth to be sharpened, they are removed from the solution andproperly washed with water oran alkaline solution to remove the acid and oiled toprevent rust. 1 IV am' aware that files have been acted upon by acids for the purpose of sharpening them. This I do not claim as my invention when done without a current of electricity.

I do not claim the general principle ot' electro-etching O r dissolving metalsin whole or in part by means of electricity, as this is known and practiced for a variety of purposes.

I do not claim any particular form of ap- 2 i einem I used in the abovedescribed proces.

vI do not', claim the use of any particular acid v or solution to the exclusion of others which The application of the electro-chemical girecess herein described; for the purpose of reentting or ehampeiing steel rasps and files in the f manner eferesai, er any other substanially the same and which will produce the intended effect.

n l WILLAM B. GILLETT.

Witnesses: I

F. G. DAY, v

J. T, LANEHART. 

